How to repair a leaking faucet handle. This one is a Delta brand but if yours is a different make you can still follow this to get the job done, you'll just have to check for the proper part number. Quick fix by replacing the stem assembly. Link below for the replacement part as well as that seat and spring that also may need replacing. As an Amazon Associate I earn from qualifying purchases, so if you're thinking of buying one for yourself please use the link below and you'll help me out. Thanks!

RP25513 Faucet Stem Replacement For Delta faucet Repair Kit + RP4993 Seat and Spring, RP24096 + RP24097 1/4 Turn Stop
https://amzn.to/39btCVP